Live male with extended yellowish-white penis; long, slender, steadily tapering to a non-mucronate tip. Not anaesthetised. Inset of same penis at same scale, contracted and distorted by boiling.

Hannaford Ellis (1979) states:
“The range of variation of the penis morphology seen in L. arcana overlaps, to a limited extent, that observed in L. rudis [=L. saxatilis]. This makes it unreliable as a diagnostic feature of either species. Nevertheless it is possible to describe a typical ‘rudis’-shape of penis and a typical ‘arcana’-shape. – – – the penis tip of L. rudis [=L.saxatilis] is frequently mucronate [= with a blunt end and small terminal point]. This never occurs in L. arcana in which the tip tapers to a point. – – – – That it is not always apparent in penes of L.rudis could be due to the killing technique [boiling water in the case of Ellis] affecting the contraction of particular muscles.”
Reid (1996) illustrates penes from live anaesthetised specimens, but they too have their shape altered from that on un-anaesthetised live specimens.

Photographs of penes on live un-anaesthetised animals may prove more reliable, but as they are time consuming to obtain, and the positions the organs are held in varies, it is unlikely that it will become a widely adopted method of identification. See P8554 & P8548

No full account yet of this species.
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